Exploration and Selection of Rhizobacteria That Inhibit Phytophthora Capsici in Vitro

Abstract

Exploration and selection of Rhizobacteria that inhibitPhytophthora capsici in vitro. Phytophthora capsici, a seed borne and the soil borne fungal pathogen is the cause of phytophthora blight on chili. The disease is difficult to control because of the unavailability of resistant varieties in Indonesia. The purpose of this study was to obtain isolates of rhizobacteria which have the ability to inhibit P. capsici in vitro. Exploration of rhizobacteria was conducted in centers of chili production in East Java (Malang, Batu, and Kediri) and West Java (Bogor). In one location, chili plant that had symptoms of phytophthora blight disease and a healthy plant next to it were chosen as samples to isolate P. capsici and the rhizobacteria. The rhizobacteria were isolated on NA, TSA, and TSAP (TSA with heated sample). Samples of diseased plants were used in isolation of P. capsici on V8 agar. The inhibition and compatibility of the rhizobacteria to inhibit P. capsici in vitro were tested by dual culture method. In this experiment, it was obtained 252 isolates of rhizobacteria and one isolate of P. capsici. Isolates of rhizobacteria with high to medium inhibition were E1, E3C2, and F2B1 respectively. All three isolates were then combined and tested against P. capsici in vitro. The highest inhibition was indicated by four isolate and combination of isolates, which were E1 isolate (58%), the combination of E1 + E3C2 isolates (58%), E1 + F2B1 (60%) and E1 + E3C2 + F2B1 (58 %). ABSTRAKEksplorasi dan penapisan Rizobakteri penghambat Phytophthora capsici secara in vitro. Phytophthora capsici, cendawan patogen terbawa benih dan tular tanah dalah penyebab penyakit busuk phytophthora pada cabai. Penyakit ini sulit dikemdalikan karena belum tersedianya varietas yang resisten di Indonesia. Tujuan penelitian ini adalah mendapatkan isolat rizobakteri yang dapat menghambat P. capsici secara in vitro. Eksplorasi rizobakteri dilakukan di sentra produksi cabai Jawa Timur (Malang, Batu, dan Kediri) dan Jawa Barat (Bogor). Setiap lokasi diambil satu sampel tanaman sehat dan satu sampel tanaman sakit bergejala busuk phytophthora yang bersebelahan. Sampel tanaman sehat digunakan dalam isolasi rizobakteri pada media NA, TSA dan TSAP (media TSA dengan sampel dipanaskan). Sampel tanaman sakit digunakan dalam isolasi P. capsici pada media agar V8. Uji daya hambat dan uji kompatibilitas rizobakteri dalam menghambat P. capsici secara in vitro diakukan dengan metode dua biakan (dual culture). Berdasarkan hasil eksplorasi diperoleh 252 isolat rizobakteri; 22 isolat diantaranya diduga memiliki kemampuan menghambat P. capsici secara in vitro, dan satu isolat P. capsici. Isolat rizobakteri dengan daya hambat tertinggi sampai sedang, berturut-turut adalah isolat E1, E3C2 dan F2B1. Hasil uji kompatibilitas tiga isolat rizobakteri terbaik menunjukkan daya hambat tertinggi serta zona penghambat terlebar terhadap P.capsici yaitu kombinasi isolat E1+F2B1 (60%), isolat E1 (58%), kombinasi isolat E1+E3C2 (58%), dan E1+E3C2+F2B1 (58%).Kata kunci: busuk phytophthora...

Potensi Rhizobakteri Tanaman Jahe Merah (Zingiber officinale Linn. Var Rubrum) di Kabupaten Halmahera Utara sebagai Agen Pemacu Pertumbuhan Tanaman

“…2, Wko 4, dan Wko 5 juga memberikan hasil tinggi antara 65-87% dibandingkan dengan kontrol. Peningkatan viabilitas dan vigor benih oleh isolat rhizobakteri diduga bahwa adanya kemampuan isolat dalam mensintesis hormon pertumbuhan, sehingga jumlah kecambah yang tumbuh normal lebih banyak (Zakia et al, 2017;Zahara & Pudjiwati, 2020).…”